Carburetor



y 1931- 7 c. E. HOFBAUER 1,807,037

CARBURETOR 2 Sheets-Sheet 1 Filed May 2. 1928 INVENTOR ATTOR May 26, 1931. c. E. HOFBAUER CARBURETOR 2 Sheets-Sheet Filed May 2, 1928 INVENTOR 0- 451 4 BY W ATTORNEY Patented May 26, 1931 UNITED STATES CASPAR E. HOFBAUER, OF NEW YORK, N. Y., ASSIGNOR TO PARAMOUNT CARBURETOR CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF PATENT. OFFICE NEW YORK CARBURETOR Application filed May 2,

My invention relates generally to a fuel feeding arrangement whereby a mixture of air and a fuel having a ratio-Which is most eflicient for varying operating conditions is supplied to an internal combustion engine in accordance with the requirement of such conditions, and in one of its phases relates to an arrangement whereby fuel from a distant storage chamber may be supplied to a level adjacent the internal combustlon engine, rendering it suitable for forming the air and fuel ratio in accordance with the requirements previously mentioned.

In its more particular embodiment my-invention contemplates the provision of a fuel feeding device at a level substantially adjacent the point of consumption of an internal combustion engine and means to supply fuel to such constant level device from a fuel supply chamber at a point distant from said constant level device, the feeding of the fuel to the constant level device being operable by a carbureting system capable of preparinga constant ratio mixture of air and fuel, the

carbureting system including a primary mixing device for air and fuel serving to lift the fuel from the constant level storage chamher and feeding the primary mixture so prepared to a secondary mixing chamber, the ratio of air to the supply from the primary mixing chamber being obtained by the air control valve responsive to variations in suc-' tion conditions of the engine in the nature of w a gravity valve, said valve being free from inaccurate responsive action by the provision of means to overcome the inertia of static or moving parts. It is further contemplated by my invention to associate witha carburetingsystem including a primary mixing chamber capable of'lifting fuel and a secondary mixing chamber utilizing the fuel as pre pared in a primary mixing chamber, the fuel being prepared in a secondary mixing chamber being converted into a mixture having a constant air-fuel ratio adapted for internal combustion engine use in accordance with all variations in the suction conditions of the engine, characterized by the provision of an air responsive gravity valve, the fuel for the carbureting system, and particularly for the 1928; Serial No. 274,423.

primary mixing chamber being obtained by a constant level intermediate storage chamber deriving its fuel supply from a distant fuel storage tank, the supply so obtained being influenced by a diminished pressure head created in said-intermediate storage chamber, the diminished pressure head being effected by the engine suction.

In another of its phases, the invention contemplates the provision of a carbureting system having a primary mixing chamber, a secondary mixing chamber utilizing the fuel prepared by the primary .mixing chamber, and an air apportioning valve responsive to all variations in the suction conditions of the engine, to be operated at all times to con- I vert the basic mixture into the final mixture, the device including a priming arrangement for supplying fuel for starting purposes and evacuating means for an interme- (113136 storage chamber whereby a constant vice. The invention still further contemplates an evacuating device for an intermediate constant level storage chamber which is free from any tendency to flood due to the in- .ertia of the flow of liquid fuel.

To attain theseobjects and such further objects as may appear herein or be hereinticularly Figure 1, I have shown the main elements of my carbureting system in which the portion A may be designated as a prilevel fuel supply is provided for the primary i 'mixing chamber and the engine priming demary mixing device, the portion B as the secondary mixing chamber, the portion C as an intermediate liquid fuel supply chamber. The assembly so described is adapted to be connected at a point adjacent an internal combustion engine, specifically with the ini nected to a flanged element 10 extending from the main'casting 11. One embodiment contemplates the provision of an air intake element 24 provided with a forwardly projecting nozzle 25, a portion of the outer wall of the latter being externally threaded to engage with the branch 26. 'It is contemplated that the atmospheric air will enter into the element 24 and will be-drawn through the nozzle 25. The branch 26 has a bore therethrough 27, into which is fitted the member 28 which comprises two conical borings 30 and 31, converging towards the central portion to a more restricted junction 32 which, however, presents a slightly larger opening than the restricted discharge 25' through the element 25.

The branch 26 ispart of a side wall of the main casting which is enlarged at 29 to re ceive the member 24, forming with the conicalportion 30 an annular chamber 33 about the outside of the nozzle 25. A boring 34 longitudinally of the branch 26 connects with this chamber for the supplying of liquid fuel thereto from the fuel chamber C by the enlarged line 34 and cross b'oring 35 therebetween, leading to the chamber. There is interposed a metering jet- 35' between the two borings 34 and 34' forpurposes as will be readily understood.

The chamber C comprises what may be termed a constant level device and includes a receptacle 36, having a capi37, including an inlet 38, depending downwardly into the receptacle. The portion 38'serves to guide and sustain the float 39 concentric therewith. The float 39 may move freely vertically upon the inlet .38 but is prevented from mounting clear to the top by the skirt 39. There is also 7 provided at the lowermost portion the bearing 40, in which are mounted the trips 41, pivoted at 42. It will be observed that the float may be free from the terminals 43'of the trips or rest upon them, serving to pivot the inner portions 44 about the pivotal portion 42. The upper portion of the cap has an upstanding flange 45, through which there is drilled an orifice 46, diametrically-thereof, as more clearly shown in Figure 1. Over this flan e I provide a cap 47 having an inlet flange 4% cooperating with the outside of the flange 45 to form an annular chamber 48. It will be observed that through the inlet of the cap 47 fluid may enter about the annular space 48 and conduct it through the orifices 46 downwardly through the flange 45, centrally whereof an inlet orifice 49 is positioned.

In the chamber formed by the flange 45 and the cap 47, a circular screen 50 is disposed, serving to protect the ingress of particles through the orifice 46, as will be understood. Extending into the orifice inlet 49 and serving to close the same, I provide a spring pressed valve 51,having a conical head 52, with itsnarrow portion downwardly disposed, the upper whereof has astem 53 serving to sustain a spring 54, maintained in position by the plug 55, having an inner portion thereof 56 threaded and engaging the flange 45, previously. An exterior'flange 57 serves to seat upon the cap and hold the same tight against the loss of fluid by the provision of a gasket 58. The shaft of thevalve 51 previously described, is guided' to be freely movable vertically within the inlet pipe 38 and to maintain the same in proper position, a bearing 59 is provided. The lower end of the shaft 51 has an enlarged head 60 which serves to engage the inner branches of the tripping members at 44.

It will be observed that with the chamber 6 I at the bottom thereof. For permitting ingress or air into the chamber 36 at predetermined rates, I preferably provide in the'cap 37 an air vent 64, connecting with the vertically drilled orifice 64. This vent is formed at the base of the boss 65, which is centrally drilled at 66 and screw threaded to retain the needle valve 67 for controlling the ingress of air through the orifice 64. A spring 68 serves to give the necessary frictional resistance to the needle valve between the base 65 and they knurled head 69, assuring a predetermined setting.

Preferably adjacent the vent previously described an additional air inlet may be supplied and for this purpose the boss 65 has an outwardly directed flange 82 interiorly drilled at 83 toconnect with the orifice 64. The outer end of the flange 82 is interiorly screw threaded at 84 to receive the fitting 85, comprising a screw-threaded sleeve interiorly orificed at 86 with a constricted opening at 87, connecting with the orifice 64' leading to the top of the chamber 36. Vents 88, cross drilled spring 94 between the lock nuts 95. Thus predetermined pressure may be exerted upon the valve 93 upon its seat.

It will be observed that the bore through the fittings 24 and 26 gives a change of velocity to any material flowing therethrough and for this purpose in my preferred form, this bore is made in the form of a Venturi tube. The venturi is made up in part of the'nozzle 25 and the bore 31, avhich communicates with the main casting. It will be observed that the nozzle 25 is so constructed as to be spaced from and project into the conically bored portion 30. It will be further observed that an annular chamber 33 is thereby produced, encircling the end of the nozzle 25 and communicating with the space between the constricted portion 25 of the nozzle and the constricted portion 32.

Before proceeding with the more detailed description of the otherclements of the carbureting system, the operation of the primary lifting means and theprimary aspirating device will be elaborated. The invention contemplates the provision of a substantial suction and flow through the venturi formed on the members. This flow not only draws air inwardly through the opening 24 and through the nozzle but it serves to form a diminished pressure head in the annular space 33 and thereby also the connecting line 34. This diminished pressure head serves to draw fuel in liquid form through the downwardly disposed inlet 34, connecting with the line 35. The reduced pressure head of this line is also utilized to form a diminished pressure head through the line 35a in the chamber 36. The fuel passing through the pipe 35 is then drawn through the restricted opening or jet 35' into the chamber 33 formed between the fittings 24 and 26. This chamber, it will be observed, is so formed as to take the form of a hollow inclined annulus, to cause the fuel to becomedischarged into the venturi at the point 32, which is the narrowest part of the venturi and there meets with and is accelerated by the flow of a solid column of air through the nozzle 25. As a result of this arrangement, to which I apply the term primary lifting and aspirating means, not only is a mixture of air and gas formed of substantially uniform character but the fuel is caused to assume a finely comminuted condition and to be mixed with air in a manner so as to form a suitable primary mixture. The parts of my carbnreting system are so arranged and constructed that this primary mixture of air and gas is of a character too rich -to be employed for ordinary engine operation and I will now proceed to describe the manner in which the primary mixture is converted into a mixture which is uniform as to its ratio of fuel to air and which is fed to the engine at a rate in accordance with re- 05 quirements under all running conditions.

Referring now more particularly to the right hand portion B of Figure 1, it will be observed that the forward end of the fitting 28 is suitably associated with and connected to a main casting or member by a driving O fit or by being threaded through the branch 7 26, integral with the casting 11.

The fitting 28 is so arranged with respect to the casting 11 as to direetthe primary mixture into an annular chamber similarto but larger than that of the annular chamber 33 of the primary mixing device shown at B. Part of the primary mixture is diverted through the orifices 31'. and part through the end of the fitting 28. This chamber will be hereinafter referred to as the secondary mixing chamber and constitutes a portion of the secondary mixing or controlling device hereinbefore referred to, tending to perfect the mixture first formed.

The secondary mixing chamber isconstituted by an upwardly disposed annular member 72, mounted with an inwardly directed flange integral with the casting 11 and arranged slightly below the fitting 28. The member 72 tapers upwardly and is of a length preferably to be in the direct path of the fuel coming in through the fitting 28 to have its edge 72 in substantial alignment with the lower edge of the fitting 28 which extends diametrically and substantially to the center of the fitting 72. \Vithin the upper portion of the casting 11 is arranged a tubularfitting or bushing 7 3 whose lower edge 7 3 is just slightly spaced from the member 7 2 and the edge 72'. The members 72 and 7 3 have I outer conical walls 7 5 and 76, respectively, forming an annular chamber 74 with an out-- let slot 74 formed by the spaced edges 72 and 7 3, respectively. The fuel from the end of cone 31 feeds the primary mixture in line with this slot and for the purpose as will be more clearly described, presently, this edge is angularly out at 28. Above the bushing 7 3 the casting 11 is provided with a flange 80, adapted for connection to the intake manifold of the engine in any of a number of well known ways and within the upper portion of the casting the usual throttle valve 81 is provided.

With a diminished pressure head within the chamber 36 as induced'by the line 35a andwith no fluid-in the chamber, the inlet 49 will be open, thereby permitting fuel to be drawn into the float chamber 36 from some distant supply chamber as the rear tank of an automobile through aline connected with the flange 47 The path of the fluid will thereafter be through the orifices 46, downwardly through the flange 45, serving to fill the chamber 36. As the float rises within the chamber, the trips41 will permit the spring pressed valve 51 to become seated, cutting off any further addition of the f delthereto and preventing flooding of the chamline 35a, the fitting 85and its assembly have ber 36. Thevent 64 giving an opening to the atmosphere within the chamber, will reestablish normal atmospheric pressures there in and will perm-it the withdrawal of liquid fuel from the chamber through the line in a manner which will be readily understood.

Should the diminished pressure within the chamber 36 be in excess of that necessary for maintaining a constant supply of fuel in the chamber, as occasioned by the differential resulting from the sizes of the vent 64 and that of the line 35a, as may be occasioned bya very rapid increase in the vacuum within the been provided. Thus a sharp increase in vacuum may be equalized within the chamber 36 above the fuel, permitting the free flow of fuel through the orifice 35, by adjusting the valve spring 94 to predetermined pressure, to admit air through the orifices.

88 if a greater vacuum is created.

.Before describing in detail the automatic operation of the elements, it may be explained that it appears that under all conditions of operation additional air is drawn upwardly through the members 72, under controlled condition, by the suction produced withil the intake manifold. This air attains a great velocity at the upper end of the members 7 2, as it-will be readily understood that the mixture whichhas been caused to whirl around the secondary mixing chamber will be picked up and directed through the fitting 7 3,a long with this additional air entering through the member 72. Additionally, mixing and vaporizing will occur as the mixture passes through the annular chamber 74, and then through the slot 74.

The controlling device comprises a conical valve 167, normally raised by gravity, closing an opening formed by an internal flange 175 4 below the member 7 2 and a conical extension 175 immediately above the same. The flange 175 constitutes the upper wall of an air intake element 176 which is substantially cylinthe admission of'air. The intake element 176 is considerably larger than the intake element 24, as is the duct 177 with respect to the opening 25 and it will be understood that the main portion of the air necessary for the formatiop of a proper mixture is supplied through the element 176. 1 r

The valve 167 is more or less controlled in its movement by the dash-pot arrangement shown as carried below the element 176. More particularly, Iyprefer to provide a chamber 180 adapted to contain liquid, and I have shown the valve 167 provided with a downwardly projecting stem 181, the latter being slidably mounted within a bearing portion 182 depending from the lower wall 183 of the air intake 17 6. At its lower end the stem 181 is provided with a piston 184 or the like, presenting an increased area to the liquid whereby the movement of the valve 167 will be suitably retarded and dampened.

The dampening piston 184 has associated therewith a secondary piston 185 in the form of a thin disc of large diameter and arranged to prevent a greater retarding surface and has a lost motion connection with the stem 181 as follows: The secondary piston 185 is received in a reduced portion of the piston 184 so as to permit of a free limited movement of the secondary piston 185. Spacing circular spurs or ridges 186 and 187 serve to hold the disc 185 away from contact with the primary piston 184. The effect of this two part damper is to provide a greater initial retardation of the upward movement of the valve 167 than on the downward movement thereof, because on the upward movement of the valve 167, the pistons 184 and 185 will move together from the time of initiation of such movement, whereas on the downward inner edge so dimensioned and arranged as to fit loosely on the piston 184so as to provide a clearance between this edge and the adj acent wall of the piston. The outside edge of the piston 185 is however so arranged as to provide a rather close fit inside of the wall or skirt 116 of the chamber180. Inside of the upper circular ridge 186, the piston 184 is provided with one or more openings 184', therethrough.

As a result ofthis arrangement, it will be understood that not only is the disc piston 185' self-aligning and always true as to its position in the chamber 180 but also upon the unseating of the disc piston 185 from its position as shown in the drawings, which occurs on the downward movement of the piston 184, a free passage is provided through the opening or openings 184 and through the clearance around the inner edge of the piston 185 -to beneath the piston 184. In this way,

the downward movement of the piston' is caused to .be made more quickly than the upper movement under thesame character of impulse.

It is of course desirable that the starting mixture have an increased richness, and in order to control the continuation of this supply of relatively rich mixture, the valve 167 may be arranged and constructed to permit manual control thereof. For this purpose, I may employ a manually controllable lever 117, the outer end of which may be operated by a lead 118, of which a spring 119 forms a part, from a suitable point on the dash-board so that it may be' controlled. The inner end of the lever is arranged to engage the upper end of. the valve 167. In this manner, what of this character is fundamentally different 4 5o amounts to an increased weight may be given the valve;

Once the engine has started, the suction will immediately operate to lift the valve 167 off of its seat. This lifting movement will be initially retarded by the piston 184 and the amount of opening produced by the valve 167 will depend upon the speed of the engine. At any constant rate of speed, the valve 167 will flutter or float at a predetermined point, to permit, the admission of a predetermined amount of air through the duct 177 It will be understood that the valve 167 will remain off its seat in all conditions of engine operation. I

It will therefore be seen that a vacuum will serve .to provide a primary or basic, somewhat vaporous' mixture throughout the running period of the engine. The parts are so proportioned and arranged that this initial mixture is richer than that required for normal automobile engine operation, and it will be observed that the secondary mixing chamber accomplishes the function, among other things, of reducing the richness of the mixture,

It will be further observed that the final richness is controlled by the amount of air supplied through the duct 177 instead of by a needle valve of the usual type which controls the amount of gasoline. Inasmuch as a suitable mixture comprises proportions of air and fuel in the neighborhood of 14 to 1, it will be obvious that the control of the 14 factor instead of the 1 factor will render inaccuracies of design and maladjustment of parts less effective in causing defective operation, I consider this an important feature of my invention.

Another-feature which I consider of great importance isthe arrangement whereby fuel in sprayed or vaporized condition is picked up from an annular chamber by air passing through said chamber in an axial direction. This feature will be clearly observed in connection with both the primary and secondary mixing chambers, and it will be obvious to those skilled in the art that an arrangement from that employed in connection with the or dinary carburetor in that conditions are attained wherein the flow induced by the intake miinifold is more accurately proportioned between air and fuel or air and fuel mixture because each agent is conditioned or prepared to be more readily responsive in supply.

' A particular feature of the present invention resides in utilizing gasoline as the retarding liquid within the chamber 180. For this purpose, the bottom of the chamber 180 1 is provided with a line 190 included by the elbow 191 as one arm and the branch 192 as .the second arm, to which latter member is connected the tube 193 extending into the chamber 34 with its end 1.94 below the jet 35' but well above the orifice 35 of the chamber 36. A fitting 195 serves to maintain the tube 193 in position in the concentric position. At the bottom end 196 of the tube .a ball valve 197 is normally held to close the tube by the spring 198, and the plug end and seal 199. It will be observed that the end 194 of the tube is positioned so that at no time will there be a complete overflow of liquid fuel from the chamber 36 to the chamber 180. This position further assures a minimum low level to the top of the tube in the channel 34. i

From above the piston I84 Within the chamber 180, a line 200 is connected with the orifice 34. Thus liquid fuel may be conducted from the chamber 180 to primary mixing chamber as will appear presently.

A particular advantage which is gained by utilizing gasoline as the retarding fluid lies in the fact that this fluidmay be utilized in modifying the richness of the mixture at certain critical periods of the running of the engine. When the engine is'suddenly accelerated, the valve 167 will tend to leap upward with a certain amount of suddenness. N ormally, this would tend to produce a momentary unduly lean mixture. While a too sudden upward movement of the valve is reincreased richness is extremely advantageous,

inasmuch as it; will be noted that this increase in richness occurs at exactly that period of running when it is most needed, namely, during rapid or instantaneous acceleration. It will also be noted that this temporary raising of additional rich liquid fuel will be but momentary. It will be observed that the one way ball valve 196 will act to permit liquid fuel to be drawn in below the piston 184 under rapid movements of the valve 167. Normal overflow or circulation about the piston ma be facilitated by the orifice 116. v

orrespondingly, when theengine throttle is suddenly closed, the retarding effect of the piston 184 will prevent choking of the engine by a possible sudden increase in richness due to the shutting olf of the air supply. Under these conditions, the ball valve 196 will be seated upon its seat, the end of the tube.

196, ,to prevent pumping of the liquid fuel into primary mixing chamber 83.

Inasmuch as it is important to prevent a sudden rise of the valve when the throttle is suddenlythrown wide open, than it would be to prevent a sudden fall, I have provided the aforementioned lost motion effect between the two part piston 184 and 185.

It will be observed that the top of the valve 167 is dished or depressed at 167 so that any condensate or excess fuel may collect in this 181' which may alsoserve to supply portion and be drained through the orififpie su cient air to vaporize the fuel collected in this dished portion upon sudden acceleration.-

. It will be obvious that in its passageto 'the point of consumption, the mixture may be preheated as by the exhaustof the engine, thereby preheating the mixture and producing advantages which will be obvious. i, It willbe understood that numerous other arrangements and consti'uctions of parts may be made to fulfill equivalent purposes and I do not mean-to limit myself to the particular structural features illustrated and described. Many changes in the details as hereindescribed and illustrated may be made by those skilled in the art without departing from the spirit and scope of the invention as expressed in the appended claims. It is therefore intended that these details be interpreted as merely illustrative, and not in a limiting sense. p

The manner in which thefuel is drawn from the rear tank to the chamber 36 is such as to always maintain the quantity of the liquid fuel within this chamber constant, regardless of the height of the fuel in the rear tank and without in any way interfering with the quantity of fuel to be drawn up for mixing in the primary mixing chamber A.

By the arrangement herein disclosed, I find that I attain a primary mixture in which the air, and fuel are mixed together so as to provide-a mixture which not only is itself stable, but the stability of which is still further increased in its travel to the point of consumptiom One of the importantfeatures of my invention is an arrangement whereby a'fuel mixture of maximum efficiency is at all times supplied for combustion purposes, and the proportion of fuel and air contained therein is maintained substantially constant regardless of running conditions, the proportion being such as to give the aforementioned maximum efliciency.

Another important feature of my. invention is the employment of a gravity valve such as that shown at 167 as the main controlling fee for of the charactr of mixture to be produced' because, not only does it control, as already stated, the air which is the large factor of the mixture, but a gravity valve presents a constant load regardless of suction conditions, and therefore moves exactly in accordance with and proportional to the variation in such suction conditions.

The shape of the valve 167 which is herein illustrated as top-like in character, possesses features of advantage in so controlling and directing the flow of air over the flange 175' as to cause it to serve its purposeswith eat efliciency inconnection with the d1rect-' mg of-the flow of air 'so that a maximum in show this valve 167 as positioned relatively close to the constricted passageway through .71 and relatively close therefore to the point at which the primary fuel mixture is introduced from the neck 71, which also I have found possesses features of advantage.

In the embodiment shown in Figures 1 and 2, the portions A and C are shown substantially in axial alignment, as will be more clearly apparent from viewing Figure 2. I may, for certain purposes, dispose the portion C containing the constant level float chamber at right angles to the portion A so that the branch 26a is in the plane of the annular chamber 33. The float chamber 360 is connected with the annular chamber 33 by the line 35; serving'to cause the for mation of a diminished pressure head within the chamber 360 for the purposes of drawing into this chamber liquid fuel from the main rear storage tank, as described in connection .with the embodiment shown in Figure 1.

this jet is substantially just above the maximum level maintained within the fuel storage chamber 360 so that whena diminished pressure head is formed by the primary mixing chamber within the annular chamber 33,

liquid fuel will flow upwardly through the jet 34'0, as fed from the line 340 and 35b.

The diminished pressure head will also serve to maintain a predetermined vacuum in the line 350 as previously described. From the line 350, at a point beyond the jet 34's I may connect a line 200 corresponding to that shown in Figure 1 and numbered 200' for the purpose of maintaining a suitable fuel levelin thechamber 180 and for priming purposes, as previously described in the corresponding member shown in Figure 1-.

By the arrangement of parts as herein described, the connections between the part A and the part B are. made internally of the branch 260, not only with greater compactness but in a manner permitting the ready supply of fuel from the intermediate\ fuel storage chamber at minimum diminished pressures, as created within the primary mixing chamber B.

It will thus be observed that I have provided a carburetor which will serve to most efliciently supply fuel for all operating conditions, such as starting, idling, rapid acceleration, rapid deceleration, change of load, hill climbing, all capable of supplying the fuel for operating an internal combustion which is adjacent to the internal combustion engine.

Having thus describedmy invention and illustrated its use, what I claim as new and 1 said chamber whereby desire to secure by Letters Patent, is

1. In a fuel feeding and carbureting device, in combination, a primary fuel mixing and evacuating device operable by the engine induction, passages thereto, one of which serves to feed fuel from an intermediate fuel storage chamber, the other of which serves to form a diminished ressure head within fuel from a low level storage tank may be caused to flow intosaid chamber and a float controlled valve for intermittently shutting" off the fuel supply to said chamber, and air valves in said chamber for limiting the diminished pressure head in said chamber within predetermined amounts.

2. In a fuel feeding and carbureting de vice, in combination, a primary fuel mixing and evacuating device, operable by the engine induction, a secondary fuel mixing chamber connected therewith, an intermediate fuel chamber, passages from said device to said fuel storage chamber, one of which is above the liquid level, a connection for a low level storage tank and a float controlled valve for said connection, an air passage to said fuel storage chamber of a size as compared to said evacuating device to form a dimmished pressure head wlthm said chamber whereby fuel from a low level storage tank may be caused to flow into said fuel storage chamber and means for admitting air to said fuel storage chamber when a predetermined pressure is obtained in said fuel storage chamber.

3. In a fuel feeding and carbureting device, in combination, a primary. mixing chamber comprising conical members having a restricted portion therebetween, a float chamber, passages connecting said float chamber with said primary mixing chamber at the restricted portion, one of which passages is disposed below the normal level of r the liquid fuel in the float chamber forming spaced conical members connected with an annular chamber, a fuel line and evacuating line connected thereto, said evacuating line being connected with a float controlled intermediate storage chamber whereby fuel may be lifted from the low level storage tank to a point adjacent the intake manifold, said fuel line being connected below the normallevel in said intermediate fuel storage chamber.

In witness whereof I have hereunto. igned my name this 24th day of April, 1928.

OASPAR E. HOFBAUER. i

retain liquid fuel and connecting passages between said cylinder and said fuel feeding passage.

4. In a fuel feeding and carbureting device, a primary mixing chamber comprising 

